Circuit-interrupter



llltilTED PATENT OFFIQE,

FREDERICK BRERETON HOLT, O ANTBOBUS, N EAR NORTHWICH, ENGLAND, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND IVJIr'lITUFfi-CTUEING COMPANY, A CORPORATION OF PENNSYLVANIA.

CIRCUIT-INTERRUPTER.

Application filed January 4, 1916.

1 b aZZ whom it may concern.-

Be it known that I, FREDERICK B. HOLT, a subject or" the King of England, and a resident of Greenfield Farm, Antrobus, near Northwich, in the county of Chester, England, have invented a new and useful Improvement in Circuit-Interrupters, of which the following is a specification.

invention relates to electric switches or circuit interrupters of the oil-immersed type, in which a movable bridging member cooperates with stationary contact members to open and close the circuit.

My invention has for its object to provide a combined guiding, accelerating and re tarding device for the moving member o1 a circuit interrupter of the above indicated character.

According to my invention, the guiding, accelerating and retarding devices comprise partially slotted tubes within which pistons or plungers, that are attached to the movable member of the circuit interrupter, are adapted to slide. In the upper ends of the guide tubes are located compression springs that coiiperate with the pistons or plunger-s to accelerate the speed of the moving member during the early part of the opening movement of the circuit interrupter. The lower ends of the guide tubes, which are not slotted, cooperate with the pistons or plungers to constitute dash pots for retarding the speed of the movable member during the latter part of the opening movement thereof.

l igure 1, of the accompanying drawings, a front elevational view of a portion of an oil-insulated circuit interrupter embodying my invention; Fig. 2 is a side view, partially in elevation and partially in section, of the circuit interrupter shown in Fig, 1 in its open position, and Fig. 3 is a vertical sectional view of the lower part of a guiding, accelerating and retarding device embodying my invention.

The circuit interrupter illustrated in the drawings comprises an oil-containing tank 1. a movable bridging member 2 of any suiteble or approved construction having contact members 13 mounted on each end thereof, stationary contact members 141 therefor and an operating rod 8 that is actuated by any suitable mechanlsm to open and close the circuit interrupter. At the middle. of

Specification of Letters Patent.

Patented Mar. 30, 1920.

Serial No. 70,320.

each side of the tank is provided a cylindrica-l guiding tube at in which a piston 5 is adapted to slide. The piston 5 is operatively connected to the movable bridging member 2 by a pin 6 that extends through longitudinally disposed slots 7 in the tubes at. The slots 7 do not extend entirely to the bottom 01" the tubes in order that the pistons 5, when descending, shall imprison a certain quantity of oil in the tubes, as herein after more fully set forth. The lower part of each of the tubes 4 is closed by a plug 8 having a suitable number of passages 9 therein by means of which oil may enter and leave the tubes. Valves, comprising washers 10 that are adapted to move vertically along pins 11 which are screwed into the plugs 8, serve to limit the flow of oil outwardly from the tubes 4} but afford little obstruction to the entry of the oil into the tubes. A compression spring 12 is located within each of the tubes l above the piston 5.

Assume that the circuit interrupter is in the closed position thereof, as shown in Fig. 1 of the drawings, and that it is desired to open the same. The movable member 2 moves downwardly to disengage the contact members. 1.3 and 14:, carrying the pistons 5 therewith. The first part of the opening movement is accelerated by the expansion of the springs 12, and the oil in the guide tubes, being permitted to readily escape through the slots 7 offers no obstruction to the clownward movement of the pistons in the tubes. However, when the bottom of the piston reaches the level of the bottom of the slots 7, the oil remaining in the lower part of the tubes 4} can only be forced out through the passages 9, but, as the valve 10 occupies the lowest or closed position, as shown in Fig. 3, the oil will be permitted to escape at only a relatively slow rate; eonsequentl the velocity of the movable member will be diminished until the end of the opening movement.

During closure of the circuit interrupter, the upward movement of the pistons will cause the oil to flow into the guide tubes 4 through the passages 9, and the valve 10, rising on the pins. 11, will offer relatively little obstruction to the entry of oil in order that the beginning of the closing movement shall not be unduly retarded. The oil in the upper part of the guide tubes at will escape through the slots 7, and, as the movable member reaches the final or closed position thereof, the springs 12 will be compressed.

It will be seen that, with my device, the opening of the circuit interrupter, which considerably accelerated by the compression springs 12, will be retarded toward the end of the opening movement thereof, and jars or shocks to the interrupter or any part of the mechanism will be prevented by the cushioning efl'ect of the oil imprisoned in the bottoms of the guide tubes. The size and shape of the slots 7 may be so varied that any desired degree of retardation or speed of travel of the movable membermay be obtained, also the size of the passages 9 and the proportions and amount of movement of the valve 10 may be so varied that such cushioning effect as may be desired may be obtained, and, at the same time, retardation of the upward'mo 'ement of tlie mem 'aer 2 during the closure of the interrupter will be avoided. ltwill also be seen that the tubes 4i, in cooperation with the pistons 5, constitute guiding devices that inire proper alinement of the contact members.

I do not wish to be restricted to the specific structural details and arrangement and location of parts shown and described, but intend to cover, in the appended claims, all modifications that do not depart from the spirit and scope of my invention.

I claim as my invention:

1. In a circuit interrupter, the combination with relat vely mo able contact members, of a unitary structure comprising means for guiding and accelerating one of said members, and a fluid controlled mea s on-the unitary structure for retarding too said member.

2. In a circuit interrupter, the combination with an oil-containing receptacle, cooperating contact memb s disposed therein, and a bridging member for the said movable contact members, of cylindrical members having openings therein for a portion of the length thereof, a coil spring disposed in the open portion of the cylindrical member, a piston normally disposed. in the open portion and adapted to be moved into the closed portion, and a valve disposed in the lower end of the said cylindrical member, said cylindrical member being immersed in the oil and adapted to guide the bridging member.

8. In a circuit interrupter, the combination with a fluid containing receptacle and relatively movable contact members therein, of a unitary structure comprising means for guiding and accelerating one of said members, and means on the unitary structure cooperating with the fluid in the receptacle for retarding said member.

l. In a circuit interrupter, the combina tion with fluid-containing receptacle and relatively movable contact members therein,-

of a single composite structure comprising a tubular member, a member in the tubular member and operatively connected to one of said contact members for guiding the same, resilient means in the tubular member for accelerating the movement of said guiding member, and a valve in the tubular member for decelerating the movement of said guiding member.

5. In a circuit interrupter, the combination with a fluid-containing receptacle and relatively movable contact members therein, of a tubular member disposed in the fluidcontaining receptacle and having an opening in the upper portion thereof and a valve in the lower portion thereof, and a spring actuated piston disposed in the tubular member and connected to one of said contact members through said opening, said piston being adapted to cooperate with the tubular meml with the spring accelerating, and to cooperate with the valve and the fluid in the receptacle for retarding the movable contact members.

6. ln circuit interrupter, the combination with a fluid-containing receptacle and relatively-movable contact members therein, of a tubular member disposed adjacent said members having a longitudinal slot in its upper portion and a valve in its lower portion, a spring in the upper portion of the tubular member, and a guiding piston disposed therein and operatively connected, through said slot, to the movable contact member, said spring operating to accelerate the movement of the movable contact member during a part of the movement thereof and the piston being adapted to cooperate with the fluid in a portion of the receptacle to retard the movement during the latter part thereof.

'7. In a circuit interrupter, the combination with a fluid receptacle, relatively-movable contact members therein, and a carrying member for one of the contact members, of a tubular member having a longitudinally slotted portion and an unslotted portion, a spring in said slotted portion, a piston in the tubular member connected to the carrying member through said slot, and a valve in the said unslotted portion.

In testimony whereof, I have hereunto subscribed my name this ninth day of December, 1915.

FREDERICIC BRERETON HOLT. ll itnesses NonMAN H. SHEARD, Jiis. STEW.-'\RT l uoonroo'r.

for guiding, to cooperate 

